Astronomers now have observational evidence for a missing class of black hole. Stellar mass black holes, those up to about 10 solar masses, are well known as the remnants of supernovae. Likewise for supermassive black holes of 10,000 solar masses or greater known to reside in the hearts of galaxies like our own. The “missing link” in astrophysics has been intermediate mass black holes, or those between 100 and 10,000 solar masses. Now, scientists at the Goddard Space Flight Center in Greenbelt Maryland have used the XMM-Newton and Swift X-ray satellites to pinpoint a likely candidate; NGC 5408 X-1, a black hole with about 1,000 to 9,000 solar masses in a galaxy about 15.8 million light years away in the constellation Centaurus. This would include an event horizon about 3,800 to 34,000 miles across. An X-ray flux occurs once every 115.5 days, strongly suggesting that NGC 5408 X-1 has a stellar companion accreting donor material. This star would be 3-5 times the Sun’s mass. “Astronomers have been studying NGC 5408 X-1… because it’s one of the best candidates for an intermediate mass black hole.” States Philip Kaaret of the University of Iowa. The contributing companion also gives astronomers the unique opportunity to probe the near-space environment as well as study this intermediate class of enigmatic objects.

Astro Documentaries

Pictured is a Delta IV rocket launch from Cape Canaveral on November 21st, 2010. The image is a 20 second exposure taken at dusk, shot from about 100 miles west of the launch site. The launch placed a classified payload in orbit for the United States Air Force.

DIY Astronomy

Difficult but not impossible to catch against the dawn or dusk sky, spotting an extreme crescent moon can be a challenge. The slender crescent pictured was shot 30 minutes before sunrise when the Moon was less than 20 hours away from New. A true feat of visual athletics to catch, a good pair of binoculars or a well aimed wide field telescopic view can help with the hunt.

The Sun is our nearest star, and goes through an 11-year cycle of activity. This image was taken via a properly filtered telescope, and shows the Sun as it appeared during its last maximum peak in 2003. This was during solar cycle #23, a period during which the Sun hurled several large flares Earthward. The next solar cycle is due to peak around 2013-14.

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Located in the belt of the constellation Orion, Messier 42, also known as the Orion Nebula is one of the finest deep sky objects in the northern hemisphere sky. Just visible as a faint smudge to the naked eye on a clear dark night, the Orion Nebula is a sure star party favorite, as it shows tendrils of gas contrasted with bright stars. M42 is a large stellar nursery, a star forming region about 1,000 light years distant.

Astronomical Observing Targets

Orbiting the planet in Low Earth Orbit (LEO) every 90 minutes, many people fail to realize that you can see the International Space Station (ISS) from most of the planet on a near-weekly basis. In fact, the ISS has been known to make up to four visible passes over the same location in one night. The image pictured is from the Fourth of July, 2011 and is a 20 second exposure of a bright ISS pass.

Next to the Sun, the two brightest objects in the sky are the Moon and the planet Venus. In fact, when Venus is favorably placed next to the Moon, it might just be possible to spot the two in the daytime. Another intriguing effect known as earthshine or ashen light is also seen in the image on the night side of the Moon; this is caused by sunlight reflected back off of the Earth towards our only satellite.

A mosaic of three images taken during the total lunar eclipse of December 21st, 2010. The eclipse occurred the same day as the winter solstice. The curve and size of the Earth’s shadow is apparent in the image.